Tie-layer adhesives are used to bond metal layers to dissimilar substrates in metal laminate applications and multi-layer, extrusion-coated structures. Tie-layer adhesives can be used in lamination, extrusion (or coextrusion), sheet extrusion, extrusion coating, injection molding, blow molding, melt thermoforming, and other processes.
Traditionally, materials in the areas of transportation, building and storage, and various other industries were fabricated from aluminum, steel, fiberglass-reinforced materials, or wood. Panels of those materials were used for making semi-trailers, truck bodies, and portable storage containers. However, an all-metal article of construction can be expensive and heavy. Also, fiberglass and wood products can gouge or splinter.
To provide cost, flexibility, and weight improvements, composite materials have been substituted for all-metal, fiberglass, and wood articles. Notably, composite systems offer the flexibility to combine the advantages of a variety of materials in their outer/facing layer and core/substrate layer, thereby permitting products which optimize price and performance. For example, outer/facing materials can include products such as acrylonitrile-butadiene-styrene, fiberglass-reinforced plastic, metals such as aluminum and stainless steel, and various other polymer products while the core/substrate materials can be made from metals such as aluminum, paper, polycarbonates, polyolefins, and polystyrene-based foam.
The construction industry provides other examples of using an adhesive to bind a metal layer to a dissimilar substrate. Examples include (a) nail-collation tape for loading nails into a nail gun, where the nails are adhered to the tape using an adhesive layer, (b) wires and cables wherein a conductive metal core is adhered to a polyolefinic layer, and (c) a multilayer pipe having a metal layer sandwiched between adjacent polyolefin-based layers wherein a tie-layer bonds the metal layer to the adjacent layers.